I. Field of the Invention
The present invention relates generally to the field of vehicle safety belts. In particular, it relates to motorized bi-level restraint at both a lap and a shoulder level of a person on a seat in a vehicle.
II. Description of the Prior Art
Automatic shoulder belts for passive safety restraint in vehicles are produced and used quite commonly. Automatic seat belts, however, are known but have not been produced as widely as the shoulder-restraining safety belts. Even though seat belts protect more of a person's body and have been designed for automatic use with automatic shoulder belts, popularity of automatic seat belts and demand for them has declined since the advent of passive restraints. Shoulder restraint alone decreases injuries from head contact with a windshield or steering wheel. However, it does not prevent injuries from lower-body contact with front portions of a vehicle. Midsections, spines, knees and most other parts of the body are left unprotected with only a shoulder belt.
Safety belts that restrain both shoulder and lap sections of a person in a vehicle are referred to as bi-level safety belts. Those that operate automatically together are known as automatic bi-level safety belts.
The concept of bi-level safety belts automatically going into a protective position when people drive and ride in cars caught attention of the public and the automobile industry alike at first. Then it died down to where only motorized shoulder belts were produced and they became a detriment to sales of cars that had them. Instead of producing known automatic bi-level safety belts, vehicle manufacturers generally have chosen to produce motorized shoulder belts separately in combination with manually operated lap belts. In the past several years, demand for motorized shoulder belts in combination with manual lap belts also has declined. Automobiles having them are hard to sell. Car manufacturers are terminating production of motorized shoulder belts, or at most providing motorized shoulder belts for only inexpensive models and some low-price cars.
People tend to use a manual lap belt even less when they have a motorized shoulder belt than when they don't have a motorized shoulder belt. They are motivated more by convenience, use of mental energy and time until they start driving. Then they think more of safety. This is not necessarily a fault, but a nature of people. According to a recent study by the National Highway Traffic Safety Administration, the current usage of manual lap belts and manual shoulder belts is about sixty percent (60%), whereas the usage of motorized shoulder belts exceeds ninety-one percent (91%).
In light of this human characteristic, a safety solution is a responsibility of producers of automobiles, not of people to function contrary to their inherent or acquired tendencies. People want safety. But they want it with conservation of their time and concern.
Reasons for decrease in demand and resulting decrease in production of bi-level safety belts and of motorized shoulder belts alone include the following:
(1) They are in the way, obtrusive and at times injurious when people get in and out of cars;
(2) The belts pass too close to heads and torsos of individuals when the belts are en route between body-release mode and body-restraint mode;
(3) They travel so fast in mode-change transit that they startle and at times injure people;
(4) They are too automated in a set routine for allowing selective variation of automated function for different individual desires and for different use conditions;
(5) Most of the problems for motorized bi-level safety belts relate to the lap belt portions; and
(6) The motorized shoulder belts alone don't provide enough protection without manual fastening of a lap belt that takes little or no more effort than fastening manual bi-level safety belts.
(7) People psychologically think they are secure in the vehicle and do not buckle lap belts.
Prior-art patents in this field include U.S. Pat. No. 3,830,518 granted Silber. Silber taught an motorized bi-level safety belt with an attachment end that traveled in a rail along a vehicle ceiling in a circular route to circumvent a body of a person on a seat in the vehicle. Then the rail went down a door post to a low seat-level position for a lap belt and to a separate higher shoulder-level position for a shoulder belt. Although its claims were broad enough to include rails positioned differently, the ceiling positioning it taught routed belts too close to an individual in order to circumvent a steering wheel. Also, it prevented use of open roofs and obstructed vision.
U.S. Pat. No. 4,070,040 granted to Igeta changed the Silber device slightly but provided substantially the same ceiling-mounted rail as taught by Silber. It had similar routing limitations although in an advanced form.
U.S. Pat. No. 4,313,622 granted to Suzuki et al teaches a thick belt for holding an attachment end of an motorized shoulder belt. The belt traveled in a rail from a front door post to a rear door post and then part way down the rear door post to a shoulder level. It did not provide for a lap belt with a second attachment end to travel to a seat level. The Suzuki device is used commonly because it omitted problems of an automated lap belt portion by omitting the lap belt itself. The Suzuki form of passive restraint in particular has deterred sales of cars with passive restraints for the reasons enumerated above. However, like some of the other forms of bi-level passive restraint, it has some features which can be utilized effectively as taught by this invention.
U.S. Pat. No. 4,392,671 granted to Fohl further advances the Suzuki device with elimination of the lap belt. It also teaches a combined door-mounted restraint that has not found popular acceptance and is not relative to this invention.
U.S. Pat. No. 5,183,291 granted to Shah describes shoulder belt track and lap belt track means that are positioned in a ceiling like the Silber patent in one embodiment. In other embodiments it is positioned variously around complete doorways of vehicles in an operational relationship similar to the Suzuki and Fohl devices. Such broad reference to means is employed in the Shah patent that it tends only to describe problems instead of structural solutions. The problems of the prior art remain unsolved. Some of those problems and others in addition are solved with this invention.
U.S. Pat. No. 5,044,664 granted to Mogi teaches an adjustable stop that could have been employed in combination with the Igeta device. But it was a different stop means than taught in this invention. Shah mentioned but did not describe stop means that could have been employed if taught for the Igeta device. Neither Mogi nor Shah taught the particular stops and separate positioning means employed for lap belts and shoulder belts in this invention.
Previous problems with motorized bi-level safety belts have been characteristics of the automation and of the safety belts, not automation of bi-level safety belts per se.